Method for accurate positioning and in-situ treatment of pollutants at sediment-water interface

Abstract

The present application relates to the technical field of water environment governance, and particularly discloses a method for accurate positioning and in-situ treatment of pollutants at a sediment-water interface. In the method, high-throughput sequencing technology and pollutant source apportionment technology are firstly used to perform accurate positioning on the sediment to be controlled, and then electrodialysis-vacuum negative pressure dewatering technology is used to perform in-situ dewatering treatment on the sediment to be controlled, thereby realizing accurate governance with the minimum desilting amount. In the present application, in further cooperation with the application of microbial reagents, the microbial flora environment of the sediment-water interface is regulated, thereby increasing the dewatering speed of the sediment.

The invention claimed is: 
     
       1. A method for positioning and in-situ treatment of pollutants at a sediment-water interface, comprising:
 determining a position of the sediment to be controlled through high-throughput sequencing analysis, wherein the high-throughput sequencing analysis comprises analyzing an abundance of an alkaline phosphatase phoD functional flora in the sediment to be controlled in molecular biology; 
 determining a depth of the sediment to be controlled based on the position of the sediment to be controlled through pollutant source apportionment, wherein the pollutant source apportionment comprises measuring emission flux of bioavailable phosphorus of the sediment to be controlled at different depths at the position of the sediment to be controlled; and 
 performing in-situ dewatering treatment on the sediment to be controlled based on the position of the sediment to be controlled and depth of the sediment to be controlled through electrodialysis-vacuum negative pressure dewatering. 
 
     
     
       2. The method according to  claim 1 , wherein performing in-situ dewatering treatment on the sediment to be controlled comprises:
 using nitrate to adjust the pH of a water body of an area to be controlled to 7.5-8.3; 
 changing a dominant flora in the sediment; and 
 placing the sediment to be controlled in an electric field, and performing dewatering treatment on the sediment under vacuum negative pressure conditions. 
 
     
     
       3. The method according to  claim 2 , wherein after using nitrate to adjust the pH of a water body of an area to be controlled to 7.5-8.3, the method further comprising:
 performing low-oxygen aeration treatment on the water body. 
 
     
     
       4. The method according to  claim 3 , wherein an oxygen aeration amount of the low-oxygen aeration is 30-60 mg/L. 
     
     
       5. The method according to  claim 3 , wherein an oxygen aeration amount of the low-oxygen aeration is 50 mg/L. 
     
     
       6. The method according to  claim 2 , wherein the electric field is an electric field with a voltage of 10-12 V and a current of 8-10 A. 
     
     
       7. The method according to  claim 2 , wherein the nitrate is sodium nitrate and/or potassium nitrate. 
     
     
       8. The method according to  claim 2 , wherein the electric field is generated by:
 placing positive and negative electrodes oppositely at an edge of the sediment to be controlled; and 
 applying a voltage of 12 V and a current of 10 A. 
 
     
     
       9. The method according to  claim 1 , wherein said determining the position of the sediment to be controlled through high-throughput sequencing analysis comprises taking sediment samples at different positions of the sediment-water interface in a river/lake water area to be controlled, extracting microbial DNA in the samples, performing 16sRNA high-throughput sequencing analysis to obtain abundance of the alkaline phosphatase phoD functional flora in the sediment samples at the different positions, and determining a sampling position of the sediment sample with the abundance of the alkaline phosphatase phoD functional flora of greater than 25% as the position of the sediment to be controlled; and
 said determining the depth of the sediment to be controlled based on the position of the sediment to be controlled through pollutant source apportionment comprises measuring emission flux of bioavailable phosphorus of the sediment at different depths at the position of the sediment to be controlled and determining a depth range where the emission flux is greater than 0.6 mg/L as the depth of the sediment to be controlled.